I have released a (historic) Cobol compiler that may be useful for someone
trying to implement such language to another OS (Linux?!). It's written mostly
in C, with a few x86 assembler routines. Included there is a debugger in prolog
(Boralnd's Turbo Prolog(TM)).
This compiler generates a code that does a simple non-preemptive multitasking
for MsDos(Microsoft, TM) and was designed for tying several microterminals to a
single PC, each one sharing the same code, but with separate data and stack
segments.
Grab the source at http://members.xoom.com/rpragana/rpcobol.tar.gz.
Everything from now on is release under GPL. Enjoy!